FYI,

Adding ports, is not something you 'just do'.

A port is a properly designed tube to control air flow. To design it properly you need to calculate the size of the 'box' used (in this case the whole boot), the properties of the sub woofer, and what frequency you want to accentuate (or not).

Just adding two 2" ports will - unless via some weird coincidence - do more harm than good.

Don't waste your time.